In 1871 he was elected as a corresponding member of the Russian Academy of Sciences, Russian language and literature department. Maksymovych also[clarification needed] was a member of the Nestor the Chronicler Historical Association that existed in Kiev in 1872-1931.

He taught biology and was director of the botanical garden at the university. During this period, he published extensively on botany and also on folklore and literature, and got to know many of the leading lights of Russian intellectual life including the Russian poet, Alexander Pushkin and Russian writer, Nikolay Gogol, and shared his growing interest in Cossack history with them.

In 1834, he was appointed professor of Russian literature at the newly created Saint Vladimir University in Kiev and also became the university's first rector, a post that he held until 1835. (This university had been established by the Russian government to reduce Polish influence in Ukraine and Maksymovych was, in part, an instrument of this policy). Maksymovych elaborated wide-ranging plans for the expansion of the university which eventually included attracting eminent Ukrainians and Russians like, Nikolay Kostomarov, and Taras Shevchenko to teach there.

In 1847, he was deeply affected by the arrest, imprisonment, and exile of the members of the Pan-Slavic Brotherhood of Saints Cyril and Methodius, many of whom, like the poet Taras Shevchenko, were his friends or students. Thereafter, he buried himself in scholarship, publishing extensively.

In 1853, he married, and in 1857, in hope of relieving his severe financial situation, went to Moscow to find work. In 1858, Shevchenko returning from exile, visited him in Moscow, and when Maksymovych returned to Mykhailova Hora, visited him there as well. At this time, Shevchenko painted portraits of both Maksimovich and his wife, Maria.

During his final years, Maksimovich devoted himself more and more to history and engaged in extensive debates with the Russian historians Mikhail Pogodin and Nikolay Kostomarov.

In the 1820s and 1830s, Maksymovych published several textbooks on biology and botany. His first scholarly book on botany was published in 1823 under the title On the System of the Flowering Kingdom. He also published popular works on botany for the layman. This "populist" approach to science, he carried over into his writings on folklore, literature, and history.

In 1833 in Moscow, he published The Book of Naum About God's Great World, which was a popularly written exposition of geology, the solar system, and the universe, in religious garb for the common folk. This book proved to be a best-seller and went through eleven editions, providing Maksimovich with some royalties for many long years.

Also in 1833, Maksymovych published "A Letter on Philosophy" which reflected his admiration for Schelling's "Nature-Philosophy." In this letter, he declared that true philosophy was based on love and that all branches of organized, systematic knowledge, which strove to recognize the internal meaning and unity of things, but most especially history, were philosophy. With his emphasis upon history, Maksimovich approached the views of Baader and Hegel as well as Schelling.

In 1827, Maksymovych published Little Russian Folksongs which was one of the first collections of folk songs published in eastern Europe. It contained 127 songs, including historical songs, songs about every-day life, and ritual songs. The collection marked a new turning to the common people, the folk, which was the hallmark of the new romantic era which was then beginning. Everywhere that it was read, it aroused the interest of the literate classes in the life of the common folk. In 1834 and in 1849, Maksymovych published two further collections.

In his collections of folksongs, Maksymovych used a new orthography for the Ukrainian language which was based on etymology. Although this Maksymovychivka looked quite similar to Russian, it was a first step towards an independent orthography, based on phonetics which was eventually proposed by Maksimovich's younger contemporary, Panteleimon Kulish. The latter forms the basis of the modern written Ukrainian language.

In general, Maksymovych claimed to see some basic psychological differences, reflecting differences in national character, between Ukrainian and Russian folk songs; he thought the former more spontaneous and lively, the latter more submissive. Such opinions were shared by many of his contemporaries such as his younger contemporary, the historian Nikolay Kostomarov and others.

In 1856, Maksymovych published the first part of his "Days and Months of the Ukrainian Villager" which summed up many years of observation of the Ukrainian peasantry. In it, he laid out the folk customs of the Ukrainian village according to the calendar year. (The full work was only published in Soviet times.)

In 1839, Maksymovych published his History of Old Russian Literature which dealt with the so-called Kievan period of Russian literature. Maksymovych saw a definite continuity between the language and literature of Ruthenia (Kievan Rus') and that of Cossack period. Indeed, he seems to have thought that the Old Ruthenian language stood in relation to modern Russian in a way similar to that of Old Czech to modern Polish or modern Slovak; that is, that one influenced but was not the same as the other. Later on, he also translated the epic Tale of Igor's Campaign into both modern Russian and modern Ukrainian verse. Maksimovich's literary works included poetry and almanacs with much material devoted to Russia.

From the 1850s to the 1870s, Maksymovych worked extensively in history, especially Russian and Ukrainian history. He was critical of the Normanist Theory which traced Kievan Rus to Scandinavian origins, preferring to stress its Slavic roots. But he opposed the Russian historian, Mikhail Pogodin, who believed that Kievan Rus originally had been populated by Great Russians from the north. Maksimovich argued that the Kievan lands were never completely de-populated, even after the Mongol invasions, and that they had always been inhabited by Ruthenians and their direct ancestors. As well, he was the first to claim the "Lithuanian period" for Russian history. Maksymovych also worked on the history of the city of Kiev, of Cossack Hetmanate, of the uprising of Bohdan Khmelnytsky, the Haidamak uprisings against Poland, and other subjects. In general, he sympathized with these various Cossack rebels, so much so, in fact, that his first work on the Haidamaks was banned by the Russian censor. Many of his most important works were critical studies and corrections of the publications of other historians, like Mikhail Pogodin and Nikolay Kostomarov.

With regard to Slavic studies, Maksimovich remarked upon the various theses of the Czech philologist, Josef Dobrovský and the Slovak scholar, Pavel Jozef Šafárik. Like them, he divided the Slavic family into two major groups, a western group and an eastern group. But then he sub-divided the western group into two further parts: a north-western group and a south-western group. (Dobrovsky had lumped the Russians together with the South Slavs.) Maksymovych particularly objected to Dobrovsky's contention that the major eastern or Russian group was unified, without major divisions or dialects. This eastern group, Maksymovych divided into two independent languages, South Russian and North Russian. The South Russian language, he divided into two major dialects, Ruthenian and Red Ruthenian/Galician. The North Russian language, he divided into four major dialects of which he thought the Muscovite the most developed, but also the youngest. In addition to this, he also seems to have considered Belarusian to be an independent language, intermediate between North and South Russian, but much closer to the former. Writing at the beginning of the twentieth century, the Croatian scholar, V. Jagic, thought Maksimovich's scheme to have been a solid contribution to Slavic philology.

Maksymovych also argued in favour of the independent origin of the spoken Old Rus languages, thinking them separate from the book language of the time which was based on Church Slavonic. Maksimovich also made some critical remarks on Pavel Jozef Šafárik's map of the Slavic world, wrote on the Lusatian Sorbs, and on Polish proverbs. Maksimovich, as well, wrote a brief autobiography which was first published in 1904. His correspondence was large and significant.

Maksymovych was a pioneer of his time and, in many ways, one of the last of the "universal men" who were able to contribute original works to both the sciences and the humanities. His works in biology and the physical sciences reflected a concern for the common man - love for his fellow human being, Schelling's philosophy, at work - and his works in literature, folklore, and history, often phrased in terms of friendly public "letters" to his scholarly opponents, pointed to new directions in telling the story of the common people. In doing this, however, Maksymovych "awakened" new national sentiments among his fellows, especially the younger generation. He greatly influenced many of his younger contemporaries including the poet Taras Shevchenko, the historian Nikolay Kostomarov, the writer Panteleimon Kulish, and many others.